1000 editions is a symbol of 1000 Orizurus.

"Sadako" was a Japanese girl that got cancer during the atomic attack on Hiroshima. She was told that she would be cured if she made a thousand pieces of Orizuru. During her illness, she made 644 Orizuru, but she passed away. Her friends made 356 other Orizurus and buried them together with Sadako.
The large crane in the photo is a symbol of pacifism & eternal peace for the world.

Orizuru or Japanese paper crane in Persian is called "Dorna".